Azo coloring matter



I uN EmsTATEsi P sta Dec. 23, 1930 ,PATENT OFFICE BYRON, L. wnsn: on AMBURG, ,NEW', 1 Yonx, ASSIGNOR TO NATIONAL ANILINE a CHEMICAL ooMP NmINo, on NEW YORK, N. Y., A CORPORATION on NEW YORK A A Azo ,oononINe MATTER No Dr wing.

7 This invention relates to'the manufacture in dyeing paper, cotton, wool, silk and other -material/ The invention includes the news dyestuffs and the material dyed wit-h the same. i r

hydrolytic decomposition. in the presence of 10 water and preferably finan alkaline medium, of thediazordisazoibody, pp -diazo-diphenyl2 azo3.6-disulfofl.8 aminonaphthol- 7 azo-benzene, having in the se saw the probable formula V g I V f Hols I SOSH a wherein represents angacidradical, preferably an inorganic acid radical 3 such a as (so-r)' /2-,'HsO4, Cl,-etc. The hydrolytic debe eifect'ed byheating the body in aqueous solution or suspension. In the decomposition, nitrogen is evolved and the dyestuff is produced. V 7

Thdcomposition and formulaof the dyes tufi' thus produced is'not definitely known; but in-view of the known-fact that a diazo body ,.upon;;hydrolytic decomposition; (i. e., decompositioniiwith evolution of nitrogen in t; he;presence of water) ordinarily produces the: corresponding hydroXy-body why the :replacementcf thediazo, group by ahydroxyh group, it appears ,probablethat the new dyes ,flor' a major part of it, has in the free stufi' state the foll'owingprobable formula;:

em on therzillustrate the invention, butit will be,

' IlDdGKStOOClvthtl) the invention isnot limited parts. (1 moli-) x1of benzidine, in the. form thereto: The parts are by weight; Example:

Application filedlOctober 24, 1927.' Serial No. 228,498.

of benzidine sulfate, is suspended in a solution comprising about 3000 parts of water C. by the addition of ice, and tetrazotized by the slow addition, with stirring, of about 116 v I A a parts of sodium nitrite of 97 percent purity, The newidyestufl'scan beprepared by the taking care that the temperature does not hours, the final solution should be clear and substantially free from insoluble material. To the tetrazo solution thus obtained, there is slowly introduced, with stirring, a solution of 270 parts (1 mol) of H-acid (i. e.,

' 8.1-amino-naphthol-3.6-disulfonic acid) obtained by treating the H-acid with 6200-6300 parts, of water and an amount of caustic plete. This ordinarily requires aboutlG-l'? stance so formed is probabl a sodiumusalt of a dlazo-monazo product 0 an acid having rise above about 15-179 C. After 2 to 3 or soda suflicient to reflect complete solution of i. the acid without showing an alkaline reac- 7 tion toward brilliant yellow paper. The mix- I tureis stirred-at a temperature of about 15? "C. until the coupling is substantially comcomposition is preferably efiected byidrying the moist and alkaline filtercake comprising the diazo-disazo body in an oven; butit may.

hours. The intermediate productor sub-e in the free state the following probable tor- I mula H2N|" (TH 4 and is obtained as a violet colored precipitate. To the reaction mass containing the diazomonazoproduct, and cooled to a temperature of about +5 C. by the addition of ice, vthere is added a solution of diazobenzene prepared by diazotizing 79 parts (1.04 mols) of aniline in any suitable manner, for GX- ample, by adding thereto 400 parts of water.

and 230 parts of 80 Bhydrochloric acid,

then slowly adding suflicient sodium nitrite (about 60 parts) to effect diazotization, keep- A ing the temperature below about +2 G.

There is then quickly added to the mixture.

thus obtained, While stirring well, a solution of 400 parts of sodium carbonate in 1200 V about'5l0 C. for about an hour or until the coupling is'completed, the precipitated dlazo-disazo body isiiltered off on a filter press, and the moist press-cake is dried 1n thin layers onenamel, i pp P in a'shelf atmospheric or vacuum drier at a -ztemperature ofa-bout 80 C. During drying concentrated sulfuricacidgiving a reddishblue solution which upon dilution with water gives, a bluish to greenish black precipitate. From a neutral bath, the dyestufi dyes cotton bluish-green shades which are discharged to awhite, or substantially so, by treatment with alkaline hydrosulfite. it is an excellent dye for union goods since it dyes cotton, wool and silk substantially the same shade;

also dyes paper'and other materiah'but' leaves cellulose acetate (Lustron) fpracti-' cally unstained.

In theaboveexample, the amount of aniline employed is somewhat in 'excess'of the heory (i. e., one mol) but'larger or smaller amountsmay be used. Smaller amounts pro duce somewhat redder shades. Benzidin'e base or other benzidine salts maybe tetrazotized in place of benzi dine sulfate. The aniline may be diazotized in the presence of sulfuric acid instead of hydrochloric acid, and

V suspended in water and boiled to effect decomposition and the dye salted out by the adwhen sulfuric acid is used, the precipitated diazo-disazo body is obtained as the sulfate.

' The benzidine, H-acid and aniline should be substantially free from any large'amount of impurities, otherwise inferior results as-to shade and yields are obtained. The filtercake is alkaline in reaction since it contains sodium carbonate. The press-cake may be dition of limeefre'e' sodium chloride; "or the reaction-mass containing the precipitated diazo-disazo body ma'y be heated to boiling to effect decomposition. Better yields are ob tained, however, by drying themoist presscake and thus avoiding the losses due to the solubility of the final dyestuif.

I claim: 1. The process of producing an azo coloring matter, which comprises subjecting to hydrolytic decomposition a diazo-disazoibody having in the free state the following probable formula:

' 'HzN on QQ H035 wherein X denotes an acid radical.

' 2. The process of producing an azo color-e ing matter, which comprises decomposing the moist, alkaline diazo-disazo body having in the free state the following probable formula bysubjecting thesanie tofa temperature not above about 80 CJQ' p .The processof producing an azo coloring matter, which comprises subjecting to hydrolytic decomposition inthe presence of water and of an alkaline substance, thefdiazodisazo body having'in the free statethe following probable formula:

wherein X denotes an acidradical.

4. A'composition whiohfcomprises as'itsf ma or component the color ng matter obtain;

able by the hydrolytic decomposition inan alkaline medium of the .diazoedisazo body having in the free state 'the following probable formula wherein X denotesa'nacidradical; said c'oloring matter in the form of its sodium saltbeing soluble in water with a bluish green'color,

being soluble, in concentrated sulfuric acid,

with a reddish blue color, anddyeing cotton, 7

W001 and'silk bluish-green shades froma neutral bath. 5. Asanew product,the-disazo dyestufi havinginthe free state the following prob-Q,

able formula:

6. As new product, the coloring matter obtainable by coupling one molecular 'proportion of: tetrazotiz'ed benzidine with one:

molecular proportion of H-acid in an acid 1 medium to form a diazo-monazo body, then treating the diazo mon'azo'body thus obtained t moist. filter-cake containing the diazo-disazo body thus produced and a quantity of the said alkaline medium to. effect the hydrolytic de-- composition of said diazo-disazobody and produce thereby-a coloring matter which in with an excess of diazo-benzene in an alkaline medlum'whereby a dlazo-dlsazo body is pro- ,120-= :duced, and then filtering off and heating the 1 the dry state in the'form of its sodium salt 'is adark powder soluble in water with a bluish-green coloration, soluble in concen-f trated sulfuric acid with" a reddish blue colso V V oration; and which from a neutral bath dyes cotton, wool and silk bluish green shades.

7. Material dyed of claim 4. V I

8. Material dyed with the dyestu fi of claim 5.

' of claim 10.

1 9. Material dyed with the coloring matter 1 of claim 6.

' '10. As a new product, the coloring matter obtainable by coupling one molecular proportion of tetrazotized benzidine with one molecular proportion ofH-acid in an acid medium'to form a diazo-monazo body, then treating the "diazo-mona zo body thus obtained with an excess of diazo-benzene in an alkaline medium whereby a ,diazo-disazobody is produced, filtering off the diazo-disazo body, suspending said body in an alkaline solution, heating said suspension to effect hydrolytic decompositionof said diazo-disazo body and salting out the resulting coloring matter from said suspension; said coloring matter being BYRON L. WEST.

withthe coloring matter 

